Roberts, J. (1999). Twentieth century;The history of the world1901 to the Present1999. PenguinPress.
Chicago Edition CitationRoberts, Jm. Twentieth Century;The History of the World1901 to the Present1999. PenguinPress, 1999.
MLA Edition CitationRoberts, Jm. Twentieth Century;The History of the World1901 to the Present1999. PenguinPress, 1999.
Warning: These citations may not always be 100% accurate.